An aqueous suspended herbicidal composition is a formulation obtained by suspending a finely-ground solid poorly water-soluble herbicidal compound in water with a surfactant, dispersant and the like, and the solid poorly water-soluble herbicidal compound has a particle size of 5 μm or less, thus, the aqueous suspended herbicidal composition is expected to manifest a relatively high effect.
A sulfonylurea compound of the formula (I):
(wherein, R1 represents a halogen atom and R2 represents a C2-4 alkyl group or cyclopropyl group.)is known as a herbicidal active ingredient in USP2005-032650A. In USP2005-032650A, aqueous suspended herbicidal compositions containing the sulfonylurea compound are known in preparation examples 2 and 3.
Aqueous formulations containing the sulfonylurea compound of the formula (I) are generally unstable and particle size of the sulfonylurea compound of the formula (I) tend to increase in the aqueous formulation under preservation conditions. The present invention provides a stable formulation containing the sulfonylurea compound, in which the sulfonylurea compound scarcely shows growth of particle under preservation conditions.